Electric vehicle chassis with removable battery module and a method for battery module replacement

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to electric powered vehicles, and more particularly, but not by way of limitation, to an electric vehicle chassis having a removable battery module and a business method of replacing the battery module.

2. Description of the Related Art

Electrical powered vehicles have been available for many years but have never been widely accepted for use due to their limited range. An electrical powered vehicle typically includes an electric motor and drive train supported on a frame and enclosed in a body. A battery or bank of batteries are supported on the frame and connect to the electric motor to provide power thereto. The battery or bank of batteries requires a separate compartment and mounting assembly, which greatly increases vehicle weight and, thus, significantly limits vehicle range. Furthermore, the battery or bank of batteries was not normally removable from the vehicle, which rendered the vehicle inoperative during charging.

Electrical powered vehicles including removable battery packs to eliminate the necessity of placing the vehicle out of service during charging have been produced. Nevertheless, the removable battery packs still require a separate compartment and mounting assembly that increases vehicle weight to the point vehicle range is impracticably limited. Accordingly, there is a long felt need for an electrical powered vehicle design that integrates a removable battery pack in an existing vehicle structure, thereby reducing the excess weight that significantly limits vehicle range.

SUMMARY OF THE INVENTION

In accordance with the present invention, an electric powered vehicle includes a chassis defining a battery module compartment and a battery module insertable into the battery module compartment of the chassis. The electric powered vehicle further includes an access door coupled to the chassis, wherein the access door pivots from a closed position over the battery module compartment to an open position exposing the battery module compartment. The battery module includes a battery tray having an ignition contact to provide an electrical connection between the battery tray and an ignition system of the electric powered vehicle and a battery insertable into the battery tray. The battery includes an ignition contact to provide an electrical connection between the battery and the battery tray.

The electric powered vehicle further includes a locking assembly for locking the battery module within the battery module compartment of the chassis. The locking assembly includes a bolt residing within a cavity in the chassis, a biasing member for biasing the bolt to an unlocked position, and an electromagnetic field generator for generating an electromagnetic field that draws the bolt to a locked position within a cavity in the battery module. The locking assembly further includes a power contact engaged by the bolt in its locked position to provide an electrical connection among a battery of the battery module, the bolt, and an electric motor of the electric powered vehicle. The locking assembly still further includes an ignition contact engaged by the electromagnetic field generator to provide an electrical connection among a battery of the battery module, the electromagnetic field generator, and an ignition system of the electric powered vehicle.

The chassis includes a chassis front having a cross-member defining a front portion of the battery module compartment and a chassis rear having a cross-member defining a rear portion of the battery module compartment. The chassis front, the chassis rear, and a body of the electric vehicle may be formed integrally in a unibody construction, wherein a section of the body spanning the chassis front and the chassis rear defines a side portion of the battery module compartment. A chassis contact may be attached to the section of the body spanning the chassis front and the chassis rear to provide an electrical connection between a battery of the battery module and an ignition system of the electric powered vehicle. Alternatively, the chassis contact may be attached to the chassis front to provide an electrical connection between a battery of the battery module and an ignition system of the electric powered vehicle. The chassis may further include a support member attached between the chassis front and the chassis rear, wherein the support member defines a side portion of the battery module compartment. The chassis contact may be attached to the support member to provide an electrical connection between a battery of the battery module and an ignition system of the electric powered vehicle.

A method of replacing a battery module of an electric powered vehicle provides a service facility including a plurality of battery modules and a system for charging the battery modules. Upon the entry into the service facility of a driver in an electric powered vehicle with a depleted battery module, the depleted battery module is removed from the electric powered vehicle and replaced with a battery module including a fully charged battery. The driver is then charged for the battery module including the fully charged battery, and the depleted battery module is recharged.

It is therefore an object of the present invention to provide a chassis defining a battery module compartment that receives a battery module therein as an integral part, thereby reducing vehicle weight and increasing vehicle range.

It is another object of the present invention to provide a battery module that easily slides into and out from the battery module compartment.

It is a further object of the present invention to provide a locking mechanism that maintains the battery module within the battery module compartment.

Still other objects, features, and advantages of the present invention will become evident to those of ordinary skill in the art in light of the following.

BRIEF DESCRIPTION OF THE DRAWINGS

<figref idref="DRAWINGS">FIG. 1</figref> is a side view illustrating an electric vehicle including an access door to a battery module compartment.

<figref idref="DRAWINGS">FIG. 2</figref> is a perspective view illustrating the electric vehicle with a battery module removed.

<figref idref="DRAWINGS">FIG. 3</figref> is a perspective view illustrating a chassis of the electric vehicle including the battery module inserted therein.

<figref idref="DRAWINGS">FIG. 4</figref> is an exploded perspective view illustrating the chassis and the battery module.

<figref idref="DRAWINGS">FIG. 5</figref> is a cutout section view of the chassis illustrating a locking assembly.

<figref idref="DRAWINGS">FIG. 6</figref> is a perspective view illustrating an alternative chassis of the electric vehicle including the battery module inserted therein.

<figref idref="DRAWINGS">FIG. 7</figref> is an exploded perspective view illustrating the alternative chassis and the battery module.

<figref idref="DRAWINGS">FIG. 8</figref> is a section view illustrating a power supply system of the electric vehicle.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As illustrated in <figref idref="DRAWINGS">FIGS. 1</figref>, <b>3</b>, and <b>4</b>, an electric vehicle <b>1</b> includes a chassis <b>5</b> defining a battery module compartment <b>25</b> for receiving a battery module <b>3</b> therein. The electric vehicle <b>1</b> further includes an access door <b>2</b> attached to the chassis <b>5</b> to provide access to the battery module compartment <b>25</b>. In addition to the chassis <b>5</b>, the battery module <b>3</b>, and the access door <b>2</b>, the electric vehicle <b>1</b> includes components well known to those of ordinary skill in the art, such as, an electric motor <b>18</b>, a drive train including a transmission, wheels, a body, a suspension system, a braking system, a steering system, seats, interior amenities, and the like. These components mount to the chassis <b>5</b> and connect together in a manner well known to those of ordinary skill in the art to form the electric vehicle <b>1</b>.

As illustrated in <figref idref="DRAWINGS">FIGS. 2–4</figref>, the chassis <b>5</b> includes a chassis front <b>6</b>, a chassis rear <b>7</b>, and a support member <b>8</b>. The chassis front <b>6</b> includes forks <b>26</b> and <b>27</b> spaced apart an appropriate distance and connected by crossbars <b>28</b> and <b>29</b> using any suitable means, such as welding. The crossbars <b>28</b> and <b>29</b> are spaced at appropriate intervals along the forks <b>26</b> and <b>27</b> to provide stability and support. A cross-member <b>30</b> attaches between the forks <b>26</b> and <b>27</b> at an interior end, using any suitable means, such as welding. The cross-member <b>30</b> defines a front portion of the battery module compartment <b>25</b> and includes a support ledge <b>31</b> for receiving and supporting the battery module <b>3</b> thereon. The forks <b>26</b> and <b>27</b> include a cylindrical cavity <b>32</b>A and <b>32</b>B, respectively, at an interior end, which forms part of a locking assembly <b>12</b> (described herein with reference to <figref idref="DRAWINGS">FIG. 5</figref>).

The chassis rear <b>7</b> includes forks <b>33</b> and <b>34</b> spaced apart an appropriate distance and connected by a crossbar <b>35</b> using any suitable means, such as welding, to provide stability and support. A cross-member <b>36</b> attaches between the forks <b>33</b> and <b>34</b> at an interior end, using any suitable means, such as welding. The cross-member <b>36</b> defines a rear portion of the battery module compartment <b>25</b> and includes a support ledge <b>37</b> for receiving and supporting the battery module <b>3</b> thereon. The forks <b>33</b> and <b>34</b> include a cylindrical cavity <b>38</b>C and <b>38</b>D, respectively, at an interior end, which forms part of the locking assembly <b>12</b> (described herein with reference to <figref idref="DRAWINGS">FIG. 5</figref>).

The support member <b>8</b> attaches at an interior side end of the chassis front <b>6</b> and the chassis rear <b>7</b> using any suitable means, such as welding, to couple the chassis front <b>6</b> and chassis rear <b>7</b> together, thereby providing stability and support. The support member <b>8</b> further defines a side portion of the battery module compartment <b>25</b> to facilitate proper positioning of the battery module <b>3</b> within the battery module compartment <b>25</b>. A chassis contact <b>9</b> attaches at an interior face of the support member <b>8</b> to aid in the delivery of power to the locking assembly <b>12</b> (described herein with reference to <figref idref="DRAWINGS">FIG. 8</figref>).

The access door <b>2</b> pivotally connects at an interior side end of the chassis front <b>6</b> and the chassis rear <b>7</b> opposite to the support member <b>8</b> using any suitable means, such as pins inserted within a cavity. The access door <b>2</b> is movable from a closed position to an open position. In the closed position, the access door <b>2</b> seals the battery module compartment <b>25</b> to lock the battery module <b>3</b> within the chassis <b>5</b>, thereby preventing dislodgment or unwanted removal of the battery module <b>3</b> from the chassis <b>5</b>. In the open position, the access door <b>2</b> exposes the battery module compartment <b>25</b> to permit access to the battery module <b>3</b> for replacement. It should be understood that, in the closed position, the access door <b>2</b> would be maintained shut using any suitable latching mechanism. Furthermore, the access door <b>2</b> may include a suitable locking mechanism operable only by a vehicle owner or authorized service technician to prevent the theft of the battery module <b>3</b>. Although the access door <b>2</b> opens upwards and attaches to the chassis <b>5</b>, those of ordinary skill in the art will recognize that the access door <b>2</b> may open downwards as well as connect to the electric vehicle <b>1</b> at other suitable locations, such as the body.

The battery module <b>3</b> includes a battery <b>4</b> and a battery tray <b>39</b> defining an enclosure for receiving the battery <b>4</b> therein. The battery tray <b>39</b> includes cylindrical cavities <b>40</b>A–D at each end, which form part of a locking assembly <b>12</b> (described herein with reference to <figref idref="DRAWINGS">FIG. 5</figref>). The battery tray <b>39</b> further includes ignition contacts <b>10</b> and <b>41</b>A–D, which aid in the delivery of power to the locking assembly <b>12</b> (described herein with reference to <figref idref="DRAWINGS">FIG. 8</figref>). The battery tray <b>39</b> still further includes power contacts <b>42</b>A and B at a front end, which aid in the delivery of power to the electric motor <b>18</b> (described herein with reference to <figref idref="DRAWINGS">FIG. 8</figref>).

The battery <b>4</b> in this preferred embodiment is a rechargeable battery, such as a nickel-zinc battery, well known to those of ordinary skill in the art. The battery <b>4</b> fits within the battery tray <b>39</b> and is held therein either through a friction fit or a suitable securing mechanism, such as a clamp, strap, or the like. The battery <b>4</b> includes ignition contacts <b>11</b> and <b>16</b>A–D, which engage the ignition contacts <b>10</b> and <b>41</b>A–D of the battery tray <b>39</b> to permit the delivery of power from the battery <b>4</b> to the locking assembly <b>12</b> (described herein with reference to <figref idref="DRAWINGS">FIG. 8</figref>). The battery <b>4</b> further includes power contacts <b>14</b>A and B at a front end, which engage the power contacts <b>42</b>A and B of the battery tray <b>39</b> to aid in the delivery of power from the battery <b>4</b> to the electric motor <b>18</b> (described herein with reference to <figref idref="DRAWINGS">FIG. 8</figref>). Although only one battery <b>4</b> is disclosed, those of ordinary skill in the art will recognize that any number of batteries connected in series to produce the same results may be utilized.

As illustrated in <figref idref="DRAWINGS">FIG. 5</figref>, a locking assembly <b>12</b> includes a bolt <b>13</b> and a natural magnet <b>17</b>, which reside in the cylindrical cavity <b>32</b>A. The locking assembly <b>12</b> further includes a coil <b>15</b>, an ignition contact <b>41</b>A connected to the coil <b>15</b>, and a power contact <b>42</b>A engaged with the cylindrical cavity <b>40</b>A. For the purposes of disclosure, only a locking assembly <b>12</b> associated with cylindrical cavities <b>32</b>A and <b>40</b>A will be described because the locking assembly <b>12</b> associated with the cylindrical cavities <b>32</b>B and <b>40</b>B is identical. Furthermore, the locking assemblies <b>12</b> associated with the cylindrical cavities <b>38</b>C and <b>40</b>C and with the cylindrical cavities <b>38</b>D and <b>40</b>D are identical, except those locking assemblies do not include a power contact as they merely lock the battery module to the rear chassis <b>7</b> and do not aid in the delivery of power from the battery <b>4</b> to the electric motor <b>18</b>.

The natural magnet <b>17</b> attaches at the rear of the cylindrical cavity <b>32</b>A using any suitable means, and the coil <b>15</b> resides within the battery tray <b>39</b> in a position encircling the cylindrical cavity <b>40</b>A. The bolt <b>13</b> slides freely within the cylindrical cavity <b>32</b>A from an unlocked to a locked position. When no power is applied to the locking assembly <b>12</b>, the natural magnet <b>17</b> draws the bolt <b>13</b> away from the cylindrical cavity <b>40</b>A and completely into the cylindrical cavity <b>32</b>A, which is the unlocked position. In the unlocked position, the battery module <b>3</b> may be removed from the chassis <b>5</b>, as the bolt <b>13</b> does not engage the battery tray <b>39</b>. Although a natural magnet <b>17</b> is disclosed, those of ordinary skill in the art will recognize other suitable means for maintaining the bolt <b>13</b> in the unlocked position, such as a spring.

When power is applied to the locking assembly <b>12</b>, the coil <b>15</b> energizes, creating an electromagnetic field that overcomes the magnetic field of the natural magnet <b>17</b>, thereby drawing the bolt <b>13</b> into the cylindrical cavity <b>40</b>A of the battery tray <b>39</b>. The coil <b>15</b> draws the bolt <b>13</b> into the cylindrical cavity <b>40</b>A until the bolt <b>13</b> engages the power contact <b>42</b>A, which is the locked position. In the locked position, the battery module <b>3</b> cannot be removed from the chassis <b>5</b>, as the bolt <b>13</b> engages the battery tray <b>39</b>. Furthermore, the bolt serves as a contact in the transfer of power from the battery <b>4</b> to the electric motor <b>18</b> (described herein with reference to <figref idref="DRAWINGS">FIG. 8</figref>). Although the preferred embodiment discloses four locking assemblies, those of ordinary skill in the art will recognize that only one is necessary to maintain the battery module <b>3</b> within the chassis <b>5</b> and to aid in the delivery of power from the battery <b>4</b> to the electric motor <b>18</b>.

As illustrated in <figref idref="DRAWINGS">FIGS. 2–5</figref>, a fully charged battery <b>4</b> is placed within a battery tray <b>39</b> to form a battery module <b>3</b>. In placing the battery <b>4</b> into the battery tray <b>39</b>, the ignition contacts <b>11</b> and <b>16</b>A–D of the battery <b>4</b> engage the ignition contacts <b>10</b> and <b>41</b>A–D of the battery tray <b>39</b>, and the power contacts <b>14</b>A and B of the battery <b>4</b> engage the power contacts <b>42</b>A and B of the battery tray <b>39</b>. The access door <b>2</b> is moved to its open position to expose the battery module compartment <b>25</b> and permit the removal of a depleted battery module <b>3</b>. At this point, the locking assembly <b>12</b> is in its unlocked position due to the absence of power. The battery module <b>3</b> is positioned on the support ledges <b>31</b> and <b>37</b> of the cross-members <b>30</b> and <b>36</b> and slid into the battery module compartment <b>25</b> until the battery module <b>3</b> contacts and resides against the support member <b>8</b>. With the battery module <b>3</b> positioned against the support member <b>8</b>, the cylindrical cavities <b>32</b>A and B and <b>38</b>C and D align with a respective cylindrical cavity <b>40</b>A–D. Furthermore, the ignition contact <b>10</b> resides completely through the battery tray <b>39</b> such that the ignition contact <b>10</b> engages the chassis contact <b>9</b> to form an electrical connection therebetween. After insertion of the battery module <b>3</b>, the access door <b>2</b> is moved to its closed position to seal the battery module compartment <b>25</b>, thereby preventing removal of the battery module <b>3</b>. Upon the application of power as described herein with reference to <figref idref="DRAWINGS">FIG. 8</figref>, the locking assembly <b>12</b> moves to its locked position to secure the battery module <b>3</b> within the battery module compartment <b>25</b>.

The chassis <b>5</b> defines a battery module compartment <b>25</b> that receives a battery module <b>3</b> therein, which becomes part of the chassis <b>5</b>, to solve the excessive weight problem associated with electrical powered vehicles. The chassis <b>5</b> includes a removed portion (i.e., the battery module compartment <b>25</b>) so that the chassis <b>5</b> incorporates the battery module <b>3</b>, thereby eliminating the necessity of a separate battery assembly. The battery module <b>3</b> completes the chassis <b>5</b>, which provides the chassis <b>5</b> with the required structural integrity, while reducing the weight of the electric powered vehicle <b>1</b> to a point where its range significantly improves over electrical powered vehicles having separate battery assemblies.

As illustrated in <figref idref="DRAWINGS">FIGS. 6 and 7</figref>, an alternative chassis <b>50</b> permits a unibody construction for the electric vehicle <b>1</b>. In a unibody construction for the electric vehicle <b>1</b>, the chassis <b>50</b> and the body of the electric vehicle <b>1</b> are formed integrally as one piece, which eliminates the need for the support member <b>8</b>. The chassis <b>50</b> is identical in design, construction, and operation to the chassis <b>5</b> and like parts have been identified with like numerals, except the support member <b>8</b> has been eliminated. With the removal of the support member <b>8</b>, the section of the body spanning the chassis front <b>6</b> and the chassis rear <b>7</b> opposite to the access door <b>2</b> forms a side portion of the battery module compartment <b>25</b>. The chassis contact <b>9</b> may be mounted to the body section in a position similar to the position on support member <b>8</b>, or, alternatively, the chassis contact <b>9</b> may be relocated from the support member <b>8</b> onto the cross-member <b>30</b>. If the chassis contact is relocated, the ignition contact <b>10</b> is relocated from the side to the front of the battery tray <b>39</b>, and the ignition contact <b>11</b> is relocated from the side to the front of the battery <b>4</b>. Similar to the chassis <b>5</b>, the ignition contact <b>11</b> of the battery <b>4</b> electrically connects with the ignition contact <b>10</b> of the battery tray <b>39</b>, and, upon the insertion of the battery module <b>3</b> into the battery module compartment <b>25</b> until the battery module <b>3</b> abuts the sidewall of the battery compartment <b>25</b>, the ignition contact <b>10</b> of the battery tray <b>39</b> electrically connects with the chassis contact <b>9</b>.

As illustrated in <figref idref="DRAWINGS">FIG. 8</figref>, a power supply system <b>23</b> includes an ignition system <b>24</b>A and a driving system <b>24</b>B. The ignition system <b>24</b>A includes an ignition switch <b>22</b>, which, in this preferred embodiment, is located on a steering column <b>21</b>. The ignition switch <b>22</b> connects at an input side to the chassis contact <b>9</b> to receive power from the battery <b>4</b> using any suitable means, such as a wire run appropriately from the chassis <b>5</b> and along the steering column <b>21</b>. The ignition switch <b>22</b> further connects at an output side to the coil <b>15</b> of a locking assembly <b>12</b> and to each coil of the remaining locking assemblies of the electric powered vehicle <b>1</b> using any suitable means, such as a wire run appropriately from the steering column <b>21</b> along the chassis <b>5</b>. A key <b>20</b> moves the ignition switch <b>22</b> from an off position to an on position that permits the delivery of power from the battery <b>4</b> to the coil <b>15</b> of a locking assembly <b>12</b> and to each coil of the remaining locking assemblies of the electric powered vehicle <b>1</b>.

The driving system <b>24</b>B includes a variable power transfer device <b>19</b>, which, in this preferred embodiment, is an accelerator pedal that operates a variable resistor, a silicon controlled resistor (SCR), and the like. The bolt <b>13</b> of a locking assembly <b>12</b> connects to the electric motor <b>18</b> to deliver power thereto from the battery <b>4</b> using any suitable means, such as a wire run appropriately from the bolt <b>13</b> along the chassis <b>5</b> and to a power input of the electric motor <b>18</b>. The variable power transfer device <b>19</b> connects at an input side to the electric motor <b>18</b> using any suitable means, such as a wire run appropriately from the electric motor <b>18</b> along the chassis <b>5</b> and to the variable power transfer device <b>19</b>. The variable power transfer device <b>19</b> connects at an output side to a bolt of an opposing locking assembly of the chassis front <b>6</b> to provide a return line to the battery <b>4</b>. The variable power transfer device <b>19</b> connects to the bolt using any suitable means, such as a wire run appropriately from the variable power transfer device <b>19</b> along the chassis <b>5</b> and to the bolt. The variable power transfer device <b>19</b> allows a vehicle operator to regulate the delivery of power from the battery <b>4</b> to the electric motor <b>18</b> and, thus, vehicle speed.

In operation, a vehicle operator places the key <b>20</b> into the ignition switch <b>22</b> and moves the ignition switch to an on position that provides power from the battery <b>4</b> to the ignition system <b>24</b>A. As a result, the coils energize, thereby drawing a respective bolt into a respective cylindrical cavity <b>40</b>A–D to lock the battery module <b>3</b> within the chassis <b>5</b>. Furthermore, the bolts associated with the driving system <b>24</b>B engage a respective power contact <b>42</b>A and B to permit the application of power from the battery <b>4</b> to the electric motor <b>18</b> under the control of the variable power transfer device <b>19</b>. Thus, engaging the variable power transfer device <b>19</b> (i.e., stepping on the accelerator pedal) furnishes power in increasing levels to the electric motor <b>18</b>, causing movement of the electric powered vehicle <b>1</b>. When a vehicle operator uses the key <b>20</b> to move the ignition switch <b>22</b> to an off position, the coils de-energize, resulting in the natural magnets drawing a respective bolt into a respective cylindrical cavity <b>32</b>A and B and <b>38</b>C and D, thereby unlocking the battery module <b>3</b> and removing power from the electric motor <b>18</b>. The electric vehicle <b>1</b> of this preferred embodiment de-energizes the coils and removes power from the electric motor <b>18</b> when the ignition switch <b>22</b> is in the off position to provide maximum conservation of the battery <b>4</b>.

The electric vehicle <b>1</b> of this preferred embodiment, which includes a chassis <b>5</b> defining a battery module compartment <b>25</b> for receiving a battery module <b>3</b> that becomes integrated with the chassis <b>5</b>, improves the effective range of the vehicle <b>1</b> by reducing vehicle weight. This increased effective range permits a service facility, whereby a customer entering a service facility with a depleted battery module <b>3</b> would have the depleted battery module <b>3</b> removed by a service technician and replaced with a battery module <b>3</b> including a fully charged battery <b>4</b>. The service facility would include a plurality of battery modules <b>3</b>, and a system for charging the battery modules <b>3</b>. After removal, the depleted battery module <b>3</b> would be charged for use by another customer. Such a service would be similar to current gas stations, except, instead of paying for gas, the customer would pay a fee for the charged battery module, which, for example, could be based on the difference in charge between the depleted and charged battery modules <b>3</b> or simply be a flat rental type fee. The customer would drive the electric vehicle <b>1</b> until the depletion of the currently installed battery module <b>3</b>, whereupon the customer would return to a service facility offering charged replacement battery modules <b>3</b>. Those of ordinary skill in the art will recognize that the electric vehicle <b>1</b> would include a gauge, whereby the charge remaining on an installed battery module <b>3</b> would be communicated to a vehicle user.

Although the present invention has been described in terms of the foregoing embodiment, such description has been for exemplary purposes only and, as will be apparent to those of ordinary skill in the art, many alternatives, equivalents, and variations of varying degrees will fall within the scope of the present invention. That scope accordingly, is not to be limited in any respect by the foregoing description; rather, it is defined only by the claims that follow.